What is seal? | Types of seals

What is seal

What is a seal?- The word is used for many things. The word seal is also used for mammal. The word seal is also used for stamp. The term seal is used in engineering also. In this article, we will learn about the seals used in engineering.

A seal is a tool or substance that is used to bind two objects together in an effort to stop them from separating or allowing anything to flow through them.

definition of seal which is used in other term is-The term “seal” refers to a piece of wax, lead, or other material that has had a distinctive design stamped into it and is attached to a document as proof of its legitimacy.

But today in this article we will discuss about the seal which is used in engineering.

Types of seals

Seals play a significant role on how well a system works. The lifespan and dependability of what is frequently thought of as a simple component can significantly impact your operations and goods.

Here is a brief overview of some of the various seal types and the uses for which they are useful.

  • Industrial Engineering Seals.
  • Mechanical Seals.
  • Automotive Seals.

Types of Industrial Engineering Seals

Various types of seals are used in heavy industries like metal, construction, wind energy, forestry, mining, and pulp and paper. These seals must function under a variety of speeds, temperatures, and environmental conditions.
The following are a few of the common types of seals used in industrial engineering applications.

  • Hydraulic seals
  • Pneumatic seals
  • Piston seals
  • LC profile seals
  • Fastener Seals
  • Integral Seals
  • Rotary shaft seals

industrial engineering seals

Hydraulic seals

Gasket-like rings known as hydraulic seals are used to close gaps between hydraulic cylinder components. Hydraulic cylinders contain a variety of parts, some of which come into contact with the fluid. Fluid cannot leak around these components because to hydraulic seals. While offering a leak-proof seal, hydraulic seals are created to fit the components of a hydraulic cylinder. Hydraulic seals and O-rings have certain similarities. However, the lip of hydraulic seals has a groove that allows components to fit within. The groove will travel over the component to create a leak-proof seal. Even if the piston of the hydraulic cylinder moves and the fluid pressure increases, the component won’t leak. By keeping the fluid contained in the appropriate container, the hydraulic seal will stop leaks around the component.

Pneumatic seals

Any of a group of seals known as pneumatic seals is employed in applications involving reciprocating or rotational motions. Although frequently found in pneumatic cylinders and valves, they perform poorly when subjected to high pressure.

When exposed to air, this kind of seal just needs a little lubrication to form a tight seal. Additionally, pneumatic seals may be subjected to high working speeds with low pressure. Several examples of this kind of design include piston seals, rod seals, flange packings, u-cups, and vee-cups.

Piston seals

Hydraulic cylinders employ piston seals or piston rings to shut off the fluid. They are located inside the cylinder head and form a tight seal with the cylinder bore to stop fluid from passing across the cylinder head. The cylinder can then stretch or retract as a result of pressure building up on one side of the piston.

LC profile seals

The expander rings in conventional two-piece geometry seals can partially dislodge in applications where pressures fluctuate fast, leading to leakage. The LC Profile Seal Offers Improved Sealability. This issue is resolved by the distinctive one-piece design of the LC Seal.

Fastener Seals

The sealing function of a fastener, such as a screw or bolt, is supported by fastener seals, which are composed of an inner rubber component used with an outside metal washer. The combination guards against potential leaks and removes any clearance gaps between the housing’s components. Bolts, screws, and tube fittings are just a few of the many uses for Dichtomatik fastener seals to offer a dependable sealing function. On threaded fasteners like bolts or threaded rods, potential leak routes are sealed up using thread, fastener, and bonded seals. Once placed, fasteners contract by a predetermined amount, narrowing the space between them and the mate components.

Integral Seals

The Integral Seal gets its name from the way it successfully combines a rubber sealing element that has been moulded in place with a stamped, machined, or plastic or metal retainer to provide an incredibly adaptable sealing device.

Rotary shaft seals

The space between fixed and rotating components is sealed off and closed with the help of rotary shaft seals, often known as oil seals or simply shaft seals. They ensure that no pollutants pass through the clearance and stop oil leaks. Shaft seals come in a variety of varieties for a variety of purposes. Applications with rotating shafts are protected in damp situations by rotary shaft seals. The rotating shaft seals stop water and dirt from entering the application and keep lubricant (oil, grease, or water) within. The vital components of ships, pumps, and tidal turbines are shielded from fluids by these sealing systems.

Types of Mechanical seals

Mechanical seals come in a variety of varieties for a variety of purposes. following are the types of mechanical seals.

  • Conventional Seals
  • Pusher Seals
  • Non pusher Seals
  • Balanced Seals
  • Unbalanced Seals
  • Cartridge Seals

mechanical seals

Conventional Seals

Commonly used on regular service machinery, conventional seals are typically less expensive. In order to service these seals, which are mounted as separate components, a greater level of operator skill is needed. A packaging substitute is provided by conventional. The evolution of face materials and elastomer options throughout time has significantly contributed to the improvement of mechanical seals as a viable choice.

However, there are several difficulties with conventional sealing. The operator must place and align the seal on the pump’s shaft or sleeve when using a conventional seal, which is a challenging process. As a result, there may be a wider margin for mistake and early failure.

Pusher Seals

To maintain seal closing forces, pusher seals need one or more springs. The revolving or stationary component of the mechanical seal may contain springs. Pusher type seals have the disadvantage that the elastomer under the primary seal face may wear out as the face moves along the shaft/sleeve during operation, limiting its ability to provide sealing at very high pressures. A dynamic secondary seal is used in pusher seals, and it travels axially with the main seal face.

Non Pusher Seals

A metal or elastomeric bellows is used by non-pusher seals to maintain seal closing forces. Applications involving dirt and high temperatures are best suited for these seals. Bellows seals can only be used in applications with medium to low pressure. A static secondary seal on non-pusher seals maintains its position against the shaft or sleeve.

Balanced Seals

A balanced seal is a mechanical seal configuration where the seal design has altered the fluid closing forces on the seal faces. The ratio of two geometric regions is known as the seal balance or balance ratio of a mechanical seal. The closing area (Ac) and the opening area(Ao) are the names of these areas. A system where the forces exerted at the seal faces are balanced is referred to as a balanced mechanical seal arrangement. Due to the lower face loading, the seal faces are lubricated more evenly, which extends the seal life. Higher operating pressures, often exceeding 200 PSIG, are where balanced mechanical seals excel. They are also a wise choice when working with liquids that are high in volatility and low in lubricity.

Unbalanced Seals

Unbalanced mechanical seal types are frequently used as a more cost-effective substitute for balance seals, which are more intricate. Due to greater control over the face film, unbalanced seals may also show less product leakage, but as a result may have a substantially lower mean time between failure. For high pressure applications or the majority of hydrocarbon uses, unbalanced seals are not advised. A balanced seal is one that has a balance ratio lower than 100%. An Unbalanced seal is one that has a balance ratio higher than 100%. The balance ratio of the majority of balanced seals is between 60 and 90 percent. The balancing ratio of the majority of Unbalanced seals is between 110 and 160 percent.

Cartridge Seals

Mechanical cartridge seals combine all of the seal components into a single assembly. As a result, both the possibility of assembly errors and the time needed for seal changes are significantly decreased. A mechanical seal cartridge is an entirely enclosed seal system with preassembled parts. This sort of seal is typically made up of a gland, sleeve, and additional hardware that enables pre-assembly. Choosing a mechanical seal of the cartridge type has the drawbacks of a greater initial cost and more space being needed.
The design of a ready-to-use cartridge seal requires a lot of information up front.

Types of Automotive seals

Automotive seals are utilised in vehicles, as the name suggests. They are the means by which systems are connected. Additionally, it shields against pollutants, stops leaks, and controls pressure. There is a broad range of high-tech sealing solutions for cars, light trucks, buses, motorbikes, and bikes. following are the types of automotive seals

  • Bearing Seals
  • Body Seals
  • Driveline Seals
  • Engine Seals
  • Steering Seals
  • Suspension Seals
  • Wheel end Seals

automotive seals

Bearing Seals

In order to prevent excessive grease loss and contamination, bearing seals—also referred to as grease seals—are used on tapered, spherical, cylindrical, and double-row bearings. To provide the first precision bearing seals for tapered roller bearings in the market, Clark Seals teamed up with The Timken Company in 1956. With the help of seals, the necessary lubricant is kept inside the bearing while also being shielded from contaminants and other dangerous particles.

Body Seals

Body seals primarily consist of gas spring seals, which are utilised in gas springs in automotive applications as well as in a variety of industrial settings, such as the car’s tailgate or bonnet, office furniture, or kitchen appliances. Gas springs are hydrodynamic tools used in automotive and general industrial applications to lift, lower, and support movements.

Driveline Seals

Driveline seals are crucial for the effective operation of cars and help to increase a vehicle’s mobility, durability, and operating time. They provide a safer and more efficient functioning and are employed in a variety of industries, including road vehicles, agriculture, and the military.

Driveline seals are nevertheless subject to normal wear and tear, leakage, and external damage, among other difficulties. Driveline seals must be constructed to a high standard in order to overcome these difficulties.

Engine Seals

The engine is unquestionably the most crucial component of any vehicle. Seals are essential to ensuring the reliable operation of the car’s heart. In order to keep oil where it belongs and to shield the engine’s internal components from dirt and debris, both of which are common on the road, seals are utilised throughout the engine. These seals are designed specifically to survive the severe temperatures and pressures present inside an engine, enabling them to perform as expected for hundreds or even thousands of miles of driving.

Steering Seals

Driving a car would be quite challenging without power steering. Basically, your power steering system aids you by providing more force, causing your car’s wheels to turn when you turn the steering wheel even little. Power steering, which is a device that depends on seals, is obviously a rather crucial element. The pump and cylinders in power steering systems all require seals to maintain pressure while making the steering responsive to changes in speed. Automobiles’ power steering systems make use of steering seals. Its purpose is to keep gears lubricated, make sure the power steering system is functioning normally, and stop dirt, sand, and water from getting into the steering system.

Suspension Seals

Dynamic and static seals are used in passive and active suspension systems to assist keep oil within. But what distinguishes dynamic seals from static ones?

A dynamic seal is used between surfaces that move relative to one another, while a static seal is used between two surfaces that do not move relative to one another. Both play a crucial role in how well your car’s suspension works.

Wheel End Seals

Wheel seals are intended to keep road debris, dirt, and other pollutants out while driving and to maintain your wheel bearing lubricant inside the wheel end. Depending on the seal, they can be put directly into the hub or onto the spindle using special installation tools.
for instance, without wheels and without shafts, a car wouldn’t be able to turn. The shafts in your car employ rotational and static seals to keep oil in and road debris out, whether it’s the half shafts that drive the front wheels or the drive shaft that manages the differential that rotates the rear wheels.


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